The present invention relates generally to alternator rectifiers and the electrical connection of the alternators rectifier bridge circuit.
An alternator is put to use in many applications, including generating alternating current in an automobile. Conventional alternators include a rotor, a stator, a rectifier bridge, housing, and a cooling fan. The rotor is typically a claw pole configuration that contains a field coil. The start and end leads of the coil are attached to slip rings that are insulated from the rotor shaft. Insulated stationary carbon brushes communicate the generated field current to the slip rings. The brushes and slip rings provide a means of maintaining electrical continuity between the stationary DC electrical supply and the rotating rotor. Direct current from the batteries is applied to the rotating field through the field terminal and insulated brushes.
The rotor is disposed within the stator. An air gap is maintained between the rotor and stator. The rotors magnetic field energizes the coils or windings of the stator at the same time to maximize the magnetic force. Since the battery and electrical system of a vehicle cannot accept or store an AC voltage, a rectifier bridge is provided to convert AC current to DC current. A rectifier bridge includes both positive and negative diodes. The diodes act as a one-way check valve switching current back and forth so that the current flows only in one direction. More specifically, when AC current reverses itself, the diode blocks the current and no current flows. Typically, AC generators or alternators use a pair of diodes for each stator winding. For example, in a three-phase alternator, three of the diodes are positive biased and another three diodes are negative biased. The use of diodes that are reversed biased with respect to each other allows for rectification of both sides of the AC sign wave.
In order to electrically interconnect the positive and negative diodes, generally a circuit board is employed. The anode of the positive diodes, the cathode of the negative diodes, and the stator windings lead are electrically interconnected to the circuit board. This arrangement requires multiple electrical interconnects reducing reliability of the overall alternator assembly, increasing manufacturing complexity and cost.
Therefore there is a need for a new and improved alternator assembly for electrically interconnecting the positive, negative, and stator windings start and end leads to form a rectifier bridge. The new and improved assembly should reduce the number of electrical interconnects, reduce manufacturing complexity, and cost.
In an aspect of the present invention, an alternator includes a plurality of positive diodes and negative diodes having an anode electrode and a cathode electrode. The alternator further includes a plurality of stator windings that have a first end and a second end. Further, a first diode plate is provided that fixes one of the plurality of positive diodes in a first orientation. Further, the alternator includes a second diode plate for fixing the negative diodes in a second orientation. Each of the anodes of the positive diodes are connected to each of the cathodes of the negative diodes and to at least one end of each of the plurality of stator windings to form a rectifier bridge circuit.
In another aspect of the present invention, a plurality of stator windings include three stator windings.
In yet another aspect of the present invention, the first diode plate is planar and the first orientation is axially oriented.
In yet another aspect of the present invention, the second diode plate is cylindrical and the second orientation is radially oriented.
In still another aspect of the present invention, the first diode plate fixes the plurality of positive diodes in the first orientation.
In still another aspect of the present invention, the second diode plate fixes the plurality of negative diodes in the second orientation.
In still another aspect of the present invention, the first diode plate fixes the plurality of negative diodes in the first orientation.
In still another aspect of the present invention, the second diode plate fixes the plurality of positive diodes in the second orientation.
These and other aspects and advantages of the present invention will become apparent upon reading the following detailed description of the invention in combination with the accompanying drawings.